I need to replace my head gasket on my 502 MPI i used head stud instead of bolts. Can i reuse the same nuts and washer.

I do on my supercharged 540s

I always test mine in a sling-shot if they bounce off my brothers head I reuse'm if the stick I get a new one.

that is the main reason to use studs in the racing world,you can reuse the hardened nut on the hardened stud over and over and you are not stressing the threads in the cast block like you would if torquing a bolt ,the cast iorn threads will pull after enough torquing cycles.

Doesn't that just tell you that you are breaking through the case hardening on that head?

Yes but have you ever tried to dig one out, he runs faster than I do and just not worth the effort.

Yes you can reuse the nuts and washer over again with no problems.